This invention further relates to the Transmitting Transceiver" by Edward R. Caudel and William R. Wilson; U.S. Ser. No. 791,629 entitled "A Clarifying Radio Receiver" by Michael J. Cochran and Edward R. Caudel; U.S. Ser. No. 791,449 entitled "An Automatically Clarifying Radio Receiver" by Michael J. Cochran and Edward R. Caudel; U.S. Ser. No. 791,254 entitled "A Computer Controlled Radio System" by Michael J. Cochran and Edward R. Caudel; U.S. Ser. No. 791,450 entitled "A Transceiver With Only One Reference Frequency" by Michael J. Cochran; U.S. Ser. No. 791,614 entitled "A Charge Transfer Device Radio System" by Michael J. Cochran; U.S. Ser. No. 791,265 entitled "A Signal Strength Measuring Transceiver" by Edward R. Caudel; U.S. Ser. No. 791,256 entitled "A Highly Selective Programmable Filter Module" by Michael J. cochran and Edward R. Caudel; U.S. Ser. No. 791,253 entitled "A Transceiver Capable of Sensing A Clear Channel" by Jerry D. Merryman, Michael J. Cochran and Edward R. Caudel; and U.S. Ser. No. 791,264 entitled " An Electronic Phase Detector Circuit" by Michael J. Cochran.
A transceiver has a transmit mode of operation and a receive mode of operation. In a receive mode, the transceiver receives radiated electronic input signals comprised of a plurality of non-overlapping frequency bands, filters one of the bands from the plurality, and converts the filtered band to audible sounds. The input signals may be amplitude modulated (AM) or single sideband signals (SSB), as an example. Similarly, in a transmit mode, a transceiver modulates electrical signals having audio frequencies, frequency shifts demodulated signals to radio frequencies of a selectable channel, and radiates the radio signals within the channel via an antenna.
In order to activate the above-indicated operations, some means must be provided for manually selecting the functions to be performed. To this end, a plurality of knobs or keys are typically provided. For example, some keys are provided for channel selection; other keys are provided for choosing a transmit or receive mode; and additional keys are provided for volume control. More sophisticated transceivers include an even greater number of keys for specifying additional functions. For example, keys may be provided for activating a sideband mode, an amplitude modulation mode, a clarifying function, a squelch function, or a selective call function.
In the past, each of these keys were individually coupled to circuitry which performed the indicated function. One of the problems with this architecture is that a large number of wires are required to couple the keys to the circuits which perform the functions. The problem becomes aggravated with sophisticated transceivers which have a larger number of keys for performing many functions. As a result of having a large number of intercoupling wires, the transceiver becomes difficult to package. For example, if the keys are packaged in a control head, and the implementing circuitry is a physically separate signal processor unit, then a large cable is required to intercouple the control head and the unit. Such a cable is both clumsy and aesthetically undesirable. Additionally, cables having large number of wires are relatively expensive.
Another problem with the above-described prior architecture is that the design is inflexible. For example, since the keys are hard-wired to the implementing circuitry, a change in the definition of a function frequently requires a change to that wiring. Further, it is difficult to add additional functions as features, since additional cable wires are required.
In comparison, the invention as herein described has none of the above identified problems. That is, a large number of operations can be manually selected via a control head without requiring a cable to the signal processing unit having a large number of wires. In one embodiment of the invention, a virtually unlimited number of functions can be specified by intercoupling the control head and processing unit with only two wires. As a result, the control head and its coupling cable is both inexpensive and aesthetically pleasing. Further, the design of the present invention is flexible in that additional functions can be added without any hardware changes and without adding additional wires in the intercoupling cable.
The invention as herein described has an added advantage over the prior art in that signals from the keyboard are preprocessed before they are received by the implementing circuitry in signal processing unit. That is, the control head includes centralized logic for converting signals from the keyboard to a format which is more readily useable by the implementing circuits. As a result, the implementing circuitry is simplified.
Accordingly, it is one object of the invention to provide an improved transceiver.
It is another object of the invention to provide a transceiver with the control head for selecting a large number of functions utilizing only a two-wire intercoupling cable.
Another object of the invention is to provide a transceiver having a control head in which additional functions can be added without hardwire changes.
Still another object of the invention is to provide a transceiver having a control head which pre-processes keyboard signals before they are sent to the implementing circuitry.